Effects of organic medium on rheological properties of silver pastes for crystalline silicon solar cells

Circuit World ◽  
2016 ◽  
Vol 42 (2) ◽  
pp. 77-83 ◽  
Author(s):  
Jun Qin ◽  
Shuxin Bai ◽  
Weijun Zhang ◽  
Zhuofeng Liu ◽  
Hailiang Wang
Keyword(s):  
Solar Cells ◽  
Rheological Properties ◽  
Screen Printing ◽  
Crystalline Silicon ◽  
Organic Medium ◽  
Silicon Solar Cells ◽  
Silver Particles ◽  
Content Type ◽  
Crystalline Silicon Solar Cells ◽  
Front Electrode

Purpose The purpose of this paper is to characterize and understand the effects of polymer binder, thixotropic agent, solvent and organic medium content on the rheological properties of silver pastes for screen printing front electrode films of solar cells. Design/methodology/approach Dispersions of silver particles (surface modified with oleic acid) in ethyl cellulose (EC) polymer solutions with and without thixotropic agent were prepared, and yield stress values were measured by setting shear stress to characterize the inter-particle interaction strength of pastes. Steady-state flow, three interval thixotropy shear test and oscillatory measurements were conducted to study the effect of EC polymer and thixotropic agent on viscosity, structure rebuilding and viscoelastic properties of electrode pastes. The effect of solvent was studied by investigating the steady viscosity of cellulose acetate butyrate (CAB) polymer solutions and Ag dispersions. Findings Weak flocculation network of silver particles was produced because of depletion flocculation. Besides the interaction between thixotropic agent micelles, EC polymer also has a significant interaction with thixotropic agent. Merely increasing EC polymer or thixotropic agent content is not the best way to prevent the layer printed from laying down. The effect of solvent on the viscosity of paste is mainly attributed to the difference of hydromechanics radius and configuration of CAB polymer in solvents. With the increase of organic medium content, the properties of electrode pastes were converted from rigidity to flexibility. Originality/value It is still a challenge to obtain high-quality front electrode films for crystalline silicon solar cells by screen printing, because of the difficulty in reducing shadowing losses while ensuring a low series resistance and high filling factor. The paste rheological properties are the key properties related to the paste’s passing ability through the meshes and resistance of paste spreading on the substrate. Organic medium as an important component of the paste is acknowledged to be used to tailor the paste’s rheological properties and have a great role in screen printing.

Effects of polymer binder on rheological properties of silver pastes for screen printing front electrode films of solar cells

2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540027 ◽  
Author(s):  
Jun Qin ◽  
Weijun Zhang ◽  
Zhuofeng Liu ◽  
Shuxin Bai
Keyword(s):  
Solar Cells ◽  
Rheological Properties ◽  
Screen Printing ◽  
Model Parameters ◽  
Silver Particles ◽  
Front Electrode ◽  
Strength Of Interaction ◽  
Fundamental Understanding ◽  
Surface Modified ◽  
Down Sweep

The purpose of the study is to characterize and improve the fundamental understanding of the effects of Ethyl Cellulose (EC) binder on the rheological properties of silver pastes for screen printing front electrode films of solar cells. Dispersions of silver particles (surface modified with oleic acid) in EC polymer solutions with and without thixotropic agent were prepared; and yield stress values were measured by setting shear stress to characterize the strength of interaction in pastes. Week flocculation network of silver particles is produced due to depletion of flocculation. EC polymer also has a significant interaction with thixotropic agent. Down-sweep flow curves of dispersions without thixotropic agent were measured and well fitted by Generalized Casson model. The model parameters p indicated that EC polymer with high molecular weight has a stronger shear-thinning ability. Steady-state flow, three interval thixotropy shear test (3ITT) and oscillatory measurements were conducted to study the effect of EC content on viscosity, structure rebuilding and viscoelastic properties of electrode pastes. Increasing EC polymer is not the best way to prevent the layer printed from laying down.

Investigation of soldering for crystalline silicon solar cells

2016 ◽  
Vol 28 (4) ◽  
pp. 222-226 ◽  
Author(s):  
Hong Yang ◽  
He Wang ◽  
Dingyue Cao
Keyword(s):  
Solar Cells ◽  
Crystalline Silicon ◽  
Quality Criterion ◽  
Silicon Solar Cells ◽  
Crystalline Silicon Solar Cell ◽  
Solar Module ◽  
Content Type ◽  
Crystalline Silicon Solar Cells ◽  
Soldering Process ◽  
Thermal Expansion Coefficients

Purpose Tabbing and stringing are the critical process for crystalline silicon solar module production. Because of the mismatch of the thermal expansion coefficients between silicon and metal, phenomenon of cell bowing, microcracks formation or cell breakage emerge during the soldering process. The purpose of this paper is to investigate the effect of soldering on crystalline silicon solar cells and module, and reveal soldering law so as to decrease the breakage rates and improve reliability for crystalline silicon solar module. Design/methodology/approach A microscopic model of the soldering process is developed by the study of the crystalline silicon solar cell soldering process in this work. And the defects caused by soldering were analyzed systematically. Findings The defects caused by soldering are analyzed systematically. The optimal soldering conditions are derived for the crystalline silicon solar module. Originality/value The quality criterion of soldering for crystalline silicon solar module is built for the first time. The optimal soldering conditions are derived for the crystalline silicon solar module. This study provides insights into solder interconnection reliability in the photovoltaic (PV) industry.

Influence of ITO layer application on electrical parameters of silicon solar cells with screen printed front electrode

2016 ◽  
Vol 33 (3) ◽  
pp. 172-175 ◽  
Author(s):  
Kazimierz Drabczyk ◽  
Jaroslaw Domaradzki ◽  
Grazyna Kulesza-Matlak ◽  
Marek Lipinski ◽  
Danuta Kaczmarek
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrical Performance ◽  
Silicon Solar Cells ◽  
Content Type ◽  
Crystalline Silicon Solar Cells ◽  
Screen Printed

Purpose The purpose of this paper was investigation and comparison of electrical and optical properties of crystalline silicon solar cells with ITO or TiO2 coating. The ITO, similar to TiO2, is very well transparent in the visible part of optical radiation; however, its low resistivity (lower that 10-3 Ohm/cm) makes it possible to use simultaneously as a transparent electrode for collection of photo-generated electrical charge carriers. This might also invoke increasing the distance between screen-printed metal fingers at the front of the solar cell that would increase of the cell’s active area. Performed optical investigation showed that applied ITO thin film fulfill standard requirements according to antireflection properties when it was deposited on the surface of silicon solar cell. Design/methodology/approach Two sets of samples were prepared for comparison. In the first one, the ITO thin film was deposited directly on the crystalline silicon substrate with highly doped emitter region. In the second case, the TCO film was deposited on the same type of silicon substrate but with additional ultrathin SiO2 passivation. The fingers lines of 80 μm width were then screen-printed on the ITO layer with two different spaces between fingers for each set. The influence of application of the ITO electrode and the type of metal electrodes patterns on the electrical performance of the prepared solar cells was investigated through optical and electrical measurements. Findings The electrical parameters such as short-circuit current (Jsc), open circuit voltage (Voc), fill factor (FF) and conversion efficiency were determined on a basis of I-V characteristics. Short-circuit current density (Jsc) was equal to 32 mA/cm2 for a solar cell with a typical antireflection layer and 31.5 mA/cm2 for the cell with ITO layer, respectively. Additionally, electroluminescence of prepared cells was measured and analysed. Originality/value The influence of the properties of ITO electrode on the electrical performance of crystalline silicon solar cells was investigated through complex optical, electrical and electroluminescence measurements.

Tailor the Rheological Properties of Silver Front Side Metallization Paste for Crystalline Silicon Solar Cells

2019 ◽  
Vol 956 ◽  
pp. 12-20
Author(s):  
Jun Qin ◽  
Wei Jun Zhang ◽  
Jin Chao Yang ◽  
Guang Bao Du ◽  
Xinan Cai
Keyword(s):  
Rheological Properties ◽  
Network Structure ◽  
Crystalline Silicon ◽  
Polymer Network ◽  
Silicon Solar Cells ◽  
Silver Particles ◽  
Silver Paste ◽  
Crystalline Silicon Solar Cells ◽  
Polymer Resin ◽  
Internal Network

The paper aims to provide the methods to tailor the rheological properties of silver paste for improving the fine line printing properties for crystalline silicon solar cells. The investigation on the internal structure model of silver paste was performed in order to understand the interaction among constituents in silver paste. Much stronger polymer network structure is formed through chain entanglements between thixotropic agent and polymer resin compared with the network structure originated from thixotropic agent. Silver particles have some association with above polymer network structure and form a stronger internal structure of silver paste together. The rheological properties were improved by tailoring the composition of polymer resin, using a combination of controlled flocculating dispersing additive and thixotropic agent, and the addition of nanosized carbon black. The strength of internal network structure can be enhanced by the design of polymer resin composition but without increasing high shear-rate viscosity. Through the combination use of controlled flocculating dispersing additive and thixotropic agent, the strength of network structure and viscosity can be improved. The depletion flocculation induced by the addition of nanosized carbon black introduces a new attraction force between silver particles and strengthens the internal network structure.

scholarly journals The preparation of oleylamine modified micro-size sphere silver particles and its application in crystalline silicon solar cells

RSC Advances ◽  
2018 ◽  
Vol 8 (30) ◽  
pp. 16866-16872 ◽  
Author(s):  
Feng Lan ◽  
Jintao Bai ◽  
Hui Wang
Keyword(s):  
Solar Cells ◽  
Crystalline Silicon ◽  
Silicon Solar Cells ◽  
Capping Agent ◽  
Silver Particles ◽  
Crystalline Silicon Solar Cells ◽  
Chemical Approach ◽  
Simple Chemical

In this paper, micro-sized silver particles were prepared using a simple chemical approach without adjusting the pH of the solution, and oleylamine as a capping agent was described to promote the dispersion of the silver particles.

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